Abstract [en]

The report summarizes the experiences of low noise asphalt pavements in Sweden. It is primarily focused on the asphalt-related factors that affect noise. It also considers the importance of road design when porous asphalt is used, an inventory of where the low noise pavements have been used in recent years, inspection of sections laid in the Stockholm region, annual cost, different types of low noise pavements and more. The most common term for low noise asphalt is porous asphalt, PA. Porous asphalt has high void content and high proportion of coarse aggregate (85%). This gives it a continuous pore system, which can lead water away and absorb some of the sound from the tires. The aim from the beginning was to improve road safety and traffic flow on the road during rain. Over time, the focus has shifted to low noise ability and are used today primarily to limit noise disturbance. In order to improve the resistance of porous asphalt, laid in two layers, an R&D project was started in 2010, with participation of suppliers, contractors, Swedish National Road and Transport Research Institute (VTI) and the Swedish Transport Administration. Three major test sections on high traffic roads with a speed of 90, 100 and 110 km/h have been built. They were laid 2010, 2012 and 2014 in the southern, central and northern parts of Sweden. Noise reduction has been 7–8 dB(A) for the new pavements and then reduced by 0.5–1 dB(A) per year. The durability of this porous asphalt has been good with stone loss or other damage occurring only to a small extent.